Volcanic eruption caught on webcam [Video]

Not only did a webcam film the June 17 eruption of Mexico's Popocatépetl volcano in time-lapse, but it even caught the shockwave racing down its slopes.

Mexico's Popocatépetl volcano has erupted some two dozen times in the last 500 years, including several outbursts in the 1990s and 2000s. With such an active volcano looming just 40 miles away from Mexico City — the world's third-largest metropolitan area — scientists have long kept a close eye on the 17,800-foot Popocatépetl, aka "Popo."

That volcanic vigil includes webcams, one of which was dutifully filming June 17 when Popocatépetl erupted again. The result is this stunning 30-second time-lapse clip:

That ripple through the air at 0:04 is a shockwave triggered by the initial explosion, followed by a torrent of boulders and other debris cascading down the slopes. The ash cloud then quickly billows into the sky, reportedly reaching a height of 28,000 feet.

It's not quite as dramatic, but the U.S. National Oceanic and Atmospheric Administration's GOES-East satellite also spotted the eruption from 22,000 miles overhead.